Poly(arylene ether) composition, method, and article

ABSTRACT

A synergistic flame retardant combination includes (a) a phosphorus salt having the formula  
                 
 
wherein M d+  is a metal ion or an onium ion; d is 1, 2, 3, or 4 according to the identity of M and its oxidation state; each occurrence of R 1  and R 2  is independently C 1 -C 18  hydrocarbyl; and each occurrence of m and n is independently 0 or 1; and (b) a phosphine compound selected from trihydrocarbylphosphines, trihydrocarbylphosphine oxides, and combinations thereof. Polymer compositions utilizing the flame retardant combination are described.

BACKGROUND OF THE INVENTION

In the plastics industry, many product applications require flameretardant plastic compositions. In some cases, this can be achieved byusing inherently flame-retardant plastics, such as halogenated polymers.In other cases, plastics that are not inherently flame-retardant arerequired, and flame retardant additives must be added to the plasticscomposition. However, many of the most effective flame retardantadditives are halogenated compounds that are currently disfavored forhealth or environmental reasons. Furthermore, when non-halogenated flameretardant additives are used, they often must be employed in highconcentrations to achieve the desired flame retardancy, and these highconcentrations detract from the desired physical properties of theplastic composition. There is therefore a need for flame-retardantcompositions that are both halogen-free and effective at lowconcentrations.

BRIEF DESCRIPTION OF THE INVENTION

The above-described and other drawbacks are alleviated by a flameretardant composition, comprising: a phosphorus salt having the formula

wherein M^(d+) is a metal ion or an onium ion; d is 1, 2, 3, or 4according to the identity of M and its oxidation state; each occurrenceof R¹ and R² is independently C₁-C₁₈ hydrocarbyl; and each occurrence ofm and n is independently 0 or 1; and a phosphine compound selected fromtrihydrocarbylphosphines, trihydrocarbylphosphine oxides, andcombinations thereof.

Another embodiment is flame-retardant plastic composition, comprising:(a) a thermoplastic resin or a thermoset resin; and (b) a flameretardant comprising (b1) a phosphorus salt having the formula

wherein M^(d+) is a metal ion or an onium ion; d is 1, 2, 3, or 4according to the identity of M and its oxidation state; each occurrenceof R¹ and R² is independently C₁-C₁₈ hydrocarbyl; and each occurrence ofm and n is independently 0 or 1; and (b2) a phosphine compound selectedfrom trihydrocarbylphosphines, trihydrocarbylphosphine oxides, andcombinations thereof.

Another embodiment is a curable composition, comprising: (a) afunctionalized poly(arylene ether) resin; (b) a curable compoundselected from triallyl cyanurate, triallyl isocyanurate, epoxy resins,bismaleimide resins, bismaleimide triazine resins, and combinationsthereof; and (c) a flame retardant, comprising (c1) a phosphorus salthaving the formula

wherein M^(d+) is a metal ion or an onium ion; d is 1, 2, 3, or 4according to the identity of M and its oxidation state; each occurrenceof R¹ and R² is independently C₁-C₁₈ hydrocarbyl; and each occurrence ofm and n is independently 0 or 1; and (c2) a phosphine compound selectedfrom trihydrocarbylphosphines, trihydrocarbylphosphine oxides, andcombinations thereof.

Other embodiments, including methods of preparing the compositions,articles prepared from the flame-retardant plastic composition, andcured compositions and articles prepared from the curable composition,are described in detail below.

DETAILED DESCRIPTION OF THE INVENTION

A first category of embodiments relates to the flame retardantcomposition itself. Thus, one embodiment is a flame retardantcomposition, comprising: a phosphorus salt having the formula

wherein M^(d+) is a metal ion or an onium ion; d is 1, 2, 3, or 4according to the identity of M and its oxidation state; each occurrenceof R¹ and R² is independently C₁-C₁₈ hydrocarbyl; and each occurrence ofm and n is independently 0 or 1; and a phosphine compound selected fromtrihydrocarbylphosphines, trihydrocarbylphosphine oxides, andcombinations thereof. The present inventors have discovered that thecombination of the phosphorus salt and the phosphine compound has asynergistic flame retardant effect that provides improved flameretardancy compared to the individual components. This advantage can beused to reduce the total amount of flame retardant required, therebyimproving physical properties of a plastic composition. Alternatively,the advantage can be used to achieve greater flame retardancy (e.g., aUL 94 rating of V-0) than was previously attainable at any tolerablelevel of flame retardant compound. The flame retardant combination issuitable for use with a wide variety of plastic compositions, includingthose comprising thermoplastic resins and those comprising thermosetresins. One specific use of the flame retardant composition is as anadditive to a curable composition comprising a functionalizedpoly(arylene ether), and a curable compound such as triallyl cyanurate,trially isocyanurate, an epoxy resin, a bismaleimide resin, abismaleimide triazine resin, or the like.

The phosphorus salt used in the flame retardant composition has theformula

wherein M^(d+) is a metal ion or an onium ion; d is 1, 2, 3, or 4according to the identity of M and its oxidation state; each occurrenceof R¹ and R² is independently C₁-C₁₈ hydrocarbyl; and each occurrence ofm and n is independently 0 or 1. As used herein, the term “hydrocarbyl”,whether used by itself, or as a prefix, suffix, or fragment of anotherterm, refers to a residue that contains only carbon and hydrogen. Theresidue may be aliphatic or aromatic, straight-chain, cyclic, bicyclic,branched, saturated, or unsaturated. It may also contain combinations ofaliphatic, aromatic, straight chain, cyclic, bicyclic, branched,saturated, and unsaturated hydrocarbon moieties. The hydrocarbylresidue, when so stated however, may contain heteroatoms over and abovethe carbon and hydrogen members of the substituent residue. Thus, whenspecifically noted as containing such heteroatoms, the hydrocarbyl orhydrocarbylene residue may also contain carbonyl groups, amino groups,hydroxyl groups, or the like, or it may contain heteroatoms within thebackbone of the hydrocarbyl residue.

In one embodiment, M^(d+) is an onium ion. Suitable onium ions include,for example, ammonium cation (NH₄ ⁺), mono-(C₁-C₁₂)-hydrocarbylammoniumcations, di-(C₁-C₁₂)-hydrocarbylammonium cations,tri-(C₁-C₁₂)-hydrocarbylammonium cations,tetra-(C₁-C₁₂)-hydrocarbylammonium cations, phosphonium cation (PH₄ ⁺),mono-(C₁-C₁₂)-hydrocarbylphosphonium cations,di-(C₁-C₁₂)-hydrocarbylphosphonium cations,tri-(C₁-C₁₂)-hydrocarbylphosphonium cations,tetra-(C₁-C₁₂)-hydrocarbylphosphonium cations, sulfonium cation (SH₃ ⁺),mono-(C₁-C₁₂)-hydrocarbylsulfonium cations, di-(C₁-C₁₂)-hydrocarbylsulfonium cations, tri-(C₁-C₁₂)-hydrocarbyl sulfonium cations, and thelike, and combinations thereof.

In another embodiment, M^(d+) is a metal ion. Suitable metal ionsinclude, for example, ions of magnesium, calcium, aluminum, antimony,tin, germanium, titanium, zinc, iron, zirconium, cerium, bismuth,strontium, manganese, lithium, sodium, potassium, and the like, andcombinations thereof. In one embodiment, M^(d+) is Al³⁺.

Referring again to the phosphorus salt structure above, in oneembodiment each occurrence of R¹ and R² is independently C₁-C₆ alkyl. Inanother embodiment, each occurrence of R¹ and R² is methyl or ethyl. Ina preferred embodiment, M is aluminum and each occurrence of m and n iszero. In another preferred embodiment, the phosphorus salt comprisesaluminum tris(diethylphosphinate).

The flame retardant composition may comprise about 5 to about 95 partsby weight of the phosphorus salt, based on 100 parts by weight total ofthe phosphorus salt and the phosphine compound. Within this range, thephosphorus salt amount may be at least about 10 parts by weight, or atleast about 20 parts by weight. Also within this range, the phosphorussalt amount may be up to about 90 weight percent, or up to about 80weight percent.

In addition to the phosphorus salt, the flame retardant compositioncomprises a phosphine compound selected from trihydrocarbylphosphines,trihydrocarbylphosphine oxides, and combinations thereof. The phosphinecompound may be a trihydrocarbylphosphine. The trihydrocarbylphosphinemay have the structure

wherein R³-R⁵ are each independently C₁-C₁₂ hydrocarbyl, with theproviso that the trihydrocarbylphosphine has at least six carbon atoms.In the context of the trihydrocarbylphosphine and thetrihydrocarbylphosphine oxide discussed below, the hydrocarbylsubstituent may include, in addition to carbon and hydrogen, a hydroxysubstituent (e.g., the hydrocarbyl substituent may be 4-hydroxyphenyl),or an ether oxygen (e.g., the hydrocarbyl substituent may be4-phenoxyphenyl). Suitable trihydrocarbylphosphines include, forexample, triphenylphosphine, allyldiphenylphosphine,diallylphenylphosphine, triallylphosphine,bis(1-naphthyl)(4-hydroxyphenyl)phosphine,bis(4-hydroxyphenyl)(1-naphthyl)phosphine,tris(4-hydroxyphenyl)phosphine, tris(1-naphthyl)phosphine,tris(2-naphthyl)phosphine,bis(4-phenoxyphenyl)(4-hydroxyphenyl)phosphine,bis(4-hydroxyphenyl)(4-phenoxyphenyl)phosphine,tris(4-phenoxyphenyl)phosphine,bis(2,4,5-trimethylphenyl)(4-hydroxyphenyl)phosphine,bis(4-hydroxyphenyl)(2,4,5-trimethylphenyl)phosphine,tris(2,4,5-trimethylphenyl)phosphine,bis(tert-butyl)(4-hydroxyphenyl)phosphine,bis(4-hydroxy-phenyl)(tert-butyl)phosphine, tris(tert-butyl)phosphine,and the like, and combinations thereof.

The phosphine compound may be a trihydrocarbylphosphine oxide. Thetrihydrocarbylphosphine oxide may have the structure

wherein R³-R⁵ are each independently C₁-C₁₂ hydrocarbyl, with theproviso that the trihydrocarbylphosphine oxide has at least six carbonatoms. Suitable trihydrocarbylphosphine oxides include, for example,triphenylphosphine oxide, allyldiphenylphosphine oxide,diallylphenylphosphine oxide, triallylphosphine oxide,bis(1-naphthyl)(4-hydroxyphenyl)phosphine oxide,bis(4-hydroxyphenyl)(1-naphthyl)phosphine oxide,tris(4-hydroxyphenyl)phosphine oxide, tris(1-naphthyl)phosphine oxide,tris(2-naphthyl)phosphine oxide,bis(4-phenoxyphenyl)(4-hydroxyphenyl)phosphine oxide,bis(4-hydroxyphenyl)(4-phenoxyphenyl)phosphine oxide,tris(4-phenoxyphenyl)phosphine oxide,bis(2,4,5-trimethylphenyl)(4-hydroxyphenyl)phosphine oxide,bis(4-hydroxyphenyl)(2,4,5-trimethylphenyl)phosphine oxide,tris(2,4,5-trimethylphenyl)phosphine oxide,bis(tert-butyl)(4-hydroxyphenyl)phosphine oxide,bis(4-hydroxy-phenyl)(tert-butyl)phosphine oxide,tris(tert-butyl)phosphine oxide, and the like, and combinations thereof.

The flame retardant composition may comprise about 5 to about 95 partsby weight of the phosphine compound, based on 100 parts by weight totalof the phosphorus salt and the phosphine compound. Within this range,the phosphine compound amount may be at least about 10 parts by weight,or at least about 20 parts by weight. Also within this range, thephosphine compound amount may be up to about 90 weight percent, or up toabout 80 weight percent.

One embodiment is a flame retardant composition comprising a phosphorussalt having the formula

wherein M^(d+) is Al³⁺, each occurrence of R¹ and R² is independentlyC₁-C₆ hydrocarbyl, and each occurrence of m and n is 0; and atrihydrocarbylphosphine oxide having the structure

wherein R³-R⁵ are each independently C₃-C₁₂ hydrocarbyl.

One embodiment is a flame retardant composition comprising aluminumtris(diethylphosphinate) and a phosphine oxide selected fromtriphenylphosphine oxide, allyldiphenylphosphine oxide, and combinationsthereof.

In one embodiment, the flame retardant composition may be prepared byblending the phosphorus salt and the phosphine compound. However, it isnot necessary for these two components to be pre-blended before additionto a polymer composition. For example, as demonstrated in the workingexamples below, the advantages of the flame retardant combination may beattained if the phosphorus salt and the phosphine compound are added asseparate components to a polymer composition that is subsequentlyintimately blended.

The flame retardant composition is useful to impart flame retardancy toa variety of polymeric compositions. Thus, a second category ofembodiments relates to a composition, comprising: (a) a thermoplasticresin or a thermoset resin; and (b) a flame retardant comprising (b1) aphosphorus salt having the formula

wherein M^(d+) is a metal ion or an onium ion; d is 1, 2, 3, or 4according to the identity of M and its oxidation state; each occurrenceof R¹ and R² is independently C₁-C₁₈ hydrocarbyl; and each occurrence ofm and n is independently 0 or 1, and (b2) a phosphine compound selectedfrom trihydrocarbylphosphines, trihydrocarbylphosphine oxides, andcombinations thereof. Combinations (blends) of thermoplastic resin andthermoset resin may be used. Thermoplastic resins suitable for use inthe composition include, for example, poly(arylene ether)s, poly(arylenesulfide)s, polyamides, polystyrenes including homopolystyrene andrubber-modified polystyrene (“high impact polystyrene” or “HIPS”),polyolefins including polyethylene and polypropylene, polyestersincluding polyarylates, polycarbonates, poly(styrene-co-acrylonitrile)s(“SAN”), poly(acrylonitrile-co-butadiene-co-styrene)s (“ABS”),poly(styrene-co-maleic anhydride)s (“SMA”),poly(acrylonitrile-co-styrene-co-acrylate)s (“ASA”), polyimides,polyamideimides, polyetherimides, polysulfones, polyethersulfones,polyketones, polyetherketones, polysiloxanes, and the like, andcombinations thereof. These thermoplastic resins and methods for theirpreparation are known in the art. Combinations (blends) of theaforementioned thermoplastic resins include, for example, poly(aryleneether)-polyamide blends, poly(arylene ether)-polystyrene blends,poly(arylene ether)-polyolefin blends, polycarbonate-polyester blends,polycarbonate-ABS blends, polycarbonate-polysiloxane blends, andpolyetherimide-polysiloxane blends. In one embodiment, the thermoplasticresin comprises a poly(arylene ether). Preferred poly(arylene ether)sinclude homopolymers of 2,6-dimethylphenol (i.e.,poly(2,6-dimethyl-1,4-phenylene ether) and copolymers of2,6-dimethylphenol and 2,3,6-trimethylphenol (i.e.,poly(2,6-dimethyl-1,4-phenylene ether-co-2,3,6-trimethyl-1,4-phenyleneether)).

Thermoset resins suitable for use in the composition include, forexample, epoxy resins, unsaturated polyester resins, polyimide resins,bismaleimide resins, bismaleimide triazine resins, cyanate ester resins,vinyl resins, benzoxazine resins, benzocyclobutene resins, acrylics,alkyds, phenol-formaldehyde resins, novolacs, resoles,melamine-formaldehyde resins, urea-formaldehyde resins,hydroxymethylfurans, isocyanates, diallyl phthalate, triallyl cyanurate,triallyl isocyanurate, unsaturated polyesterimides, and the like, andcombinations thereof. In one embodiment, the thermoset resin comprisesan epoxy resin. In another embodiment, the thermoset resin comprisestriallyl cyanurate. In another embodiment, the thermoset resin comprisestriallyl isocyanurate.

Particularly suitable epoxy resins include those described by thestructure

wherein A is an organic or inorganic radical of valence n, X is oxygenor nitrogen, m is 1 or 2 and consistent with the valence of X, and n isfrom 1-1000 ideally 2-8, most preferably 2-4.

Suitable epoxy resins include those produced by the reaction ofepichlorohydrin or epibromohydrin with a phenolic compound. Suitablephenolic compounds include, for example, resorcinol, catechol,hydroquinone, 2,6-dihydroxy naphthalene, 2,7-dihydroxynapthalene,2-(diphenylphosphoryl)hydroquinone,bis(2,6-dimethylphenol)2,2′-biphenol, 4,4-biphenol,2,2′,6,6′-tetramethylbiphenol, 2,2′,3,3′,6,6′-hexamethylbiphenol,3,3′,5,5′-tetrabromo-2,2′6,6′-tetramethylbiphenol,3,3′-dibromo-2,2′,6,6′-tetramethylbiphenol,2,2′,6,6′-tetramethyl-3,3′5-dibromobiphenol, 4,4′-isopropylidenediphenol(bisphenol A), 4,4′-isopropylidenebis(2,6-dibromophenol)(tetrabromobisphenol A), 4,4′-isopropylidenebis(2,6-dimethylphenol)(teramethylbisphenol A), 4,4′-isopropylidenebis(2-methylphenol),4,4′-isopropylidenebis(2-allylphenol),4,4′(1,3-phenylenediisopropylidene)bisphenol (bisphenol M),4,4′-isopropylidenebis(3-phenylphenol)4,4′-(1,4-phenylenediisoprqylidene)bisphenol(bisphenol P), 4,4′-ethylidenediphenol (bisphenol E), 4,4′oxydiphenol,4,4′thiodiphenol, 4,4′thiobis(2,6-dimethylphenol), 4,4′-sufonyldiphenol,4,4′-sufonylbis(2,6-dimethylphenol) 4,4′sulfinyldiphenol,4,4′-hexafluoroisoproylidene)bisphenol (Bisphenol AF),4,4′(1-phenylethylidene)bisphenol (Bisphenol AP),bis(4-hydroxyphenyl)-2,2-dichloroethylene (Bisphenol C),bis(4-hydroxyphenyl)methane (Bisphenol-F),bis(2,6-dimethyl-4-hydroxyphenyl)methane,4,4′-(cyclopentylidene)diphenol, 4,4′-(cyclohexylidene)diphenol(Bisphenol Z), 4,4′-(cyclododecylidene)diphenol4,4′-(bicyclo[2.2.1]heptylidene)diphenol,4,4′-(9H-fluorene-9,9-diyl)diphenol,3,3-bis(4-hydroxyphenyl)isobenzofuran-1(3H)-one,1-(4-hydroxyphenyl)-3,3-dimethyl-2,3-dihydro-1H-inden-5-ol,1-(4-hydroxy-3,5-dimethylphenyl)-1,3,3,4,6-pentamethyl-2,3-dihydro-1H-inden-5-ol,3,3,3′,3′-tetramethyl-2,2′,3,3′-tetrahydro-1,1′-spirobi[indene]-5,6′-diol(Spirobiindane), dihydroxybenzophenone (bisphenol K),tris(4-hydroxyphenyl)methane, tris(4-hydroxyphenyl)ethane,tris(4-hydroxyphenyl)propane, tris(4-hydroxyphenyl)butane,tris(3-methyl-4-hydroxyphenyl)methane,tris(3,5-dimethyl-4-hydroxyphenyl)methane,tetrakis(4-hydroxyphenyl)ethane,tetrakis(3,5-dimethyl-4-hydroxyphenyl)ethane,bis(4-hydroxyphenyl)phenylphosphine oxide,dicyclopentadienylbis(2,6-dimethyl phenol), dicyclopentadienylbis(2-methylphenol), dicyclopentadienyl bisphenol, and the like, andmixtures thereof.

Other suitable epoxy resins include N-glycidyl phthalimide, N-glycidyltetrahydrophthalimide, phenyl glycidyl ether, p-butylphenyl glycidylether, styrene oxide, neohexene oxide, ethylene glycol diglycidyl ether,polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether,polypropylene glycol diglycidyl ether, tetramethyleneglycol diglycidylether, polytetramethylene glycol diglycidyl ether, bisphenol A-typeepoxy compounds, bisphenol S-type epoxy compounds, resorcinol-type epoxycompounds, phenol novolac-type epoxy compounds, cresol novolac-typeepoxy compounds, adipic acid diglycidyl ester, sebacic acid diglycidylester, phthalic acid diglycidyl ester, and the like, and mixturesthereof.

Also suitable as epoxy resins are the glycidyl ethers of phenolic resinssuch as the glycidyl ethers of phenol-formaldehyde novolac, alkylsubstituted phenol-formaldehyde resins including cresol-formaldehydenovolac, t-butylphenol-formaldehyde novolac,sec-butylphenol-formaldehyde novolac, tert-octylphenol-formaldehydenovolac, cumylphenol-formaldehyde novolac, decylphenol-formaldehdyenovolacs, and the like. Other useful epoxies are the glycidyl ethers ofbromophenol-formaldehdye novolac, chlorophenol-formaldehyde novolac,phenol-bis(hydroxymethyl)benzene novolac,phenol-bis(hydroxymethylbiphenyl) novolac, phenol-hydroxybenzaldehydenovolac, phenol-dicyclopentadiene novolac, naphthol-formaldehydenovolac, naphthol-bis(hydroxymethyl)benzene novolac,naphthol-bis(hydroxymethylbiphenyl) novolac,naphthol-hydroxybenzaldehyde novolac, naphthol-dicyclopentadienenovolacs, and the like, and mixtures thereof.

Also suitable as epoxy resins are the polyglycidyl ethers of polyhydricaliphatic alcohols. Examples of such polyhydric alcohols that may bementioned are 1,4-butanediol, 1,6-hexanediol, polyalkylene glycols,glycerol, trimethylolpropane, 2,2-bis(4-hydroxy-cyclohexyl)propane andpentaerythritol.

Curing agents for the epoxy resins include amine compounds, anhydrides,benzenediol compounds, bisphenol resin, polyhydric phenol resin,phenolic resins, and the like. Examples of the amine compounds includealiphatic amine compounds, such as diethylene triamine (DETA),triethylene tetramine (TETA), tetraethylene pentamine (TEPA),diethylaminopropylamine (DEAPA), methylene diamine, N-aminoethylpyrazine(AEP), m-xylylene diamine (MXDA) and the like; aromatic amine compoundssuch as m-phenylene diamine (MPDA), 4,4′-diaminodiphenylmethane (MDA),diaminodiphenylsulfone (DADPS), diaminodiphenyl ether and the like; andsecondary or tertiary amine compounds such as phenylmethyldimethylamine(BDMA), dimethylaminomethylphenol (DMP-10),tris(dimethylaminomethyl)phenol (DMP-30), piperidine,4,4′-diaminodicyclohexylmethane, 1,4-diaminocyclohexane,2,6-diaminopyridine, m-phenylenediamine, p-phenylenediamine,4,4′-diaminodiphenylmethane, 2,2′-bis(4-aminophenyl)propane, benzidine,4,4′-diaminophenyl oxide, 4,4′-diaminodiphenylsulfone,bis(4-aminophenyl)phenylphosphine oxide, bis(4-aminophenyl)methylamine,1,5-diaminonaphthalene, m-xylenediamine, p-xylenediamine,hexamethylenediamime, 6,6′-diamine-2,2′-pyridyl,4,4′-diaminobenzophenone, 4,4′-diaminoazobenzene,bis(4-aminophenyl)phenylmethane, 1,1-bis(4-aminophenyl)cyclohexane,1,1-bis(4-amino-3-methylphenyl)cyclohexane,2,5-bis(m-aminophenyl)-1,3,4-oxadiazole,2,5-bis(p-aminophenyl)-1,3,4-oxadiazole,2,5-bis(m-aminophenyl)thiazo(4,5-d)thiazole,5,5′-di(m-aminophenyl)-(2,2′)-bis-(1,3,4-oxadiazolyl),4,4′-diaminodiphenylether, 4,4′-bis(p-aminophenyl)-2,2′-dithiazole,m-bis(4-p-aminophenyl-2-thiazolyl)benzene, 4,4′-diaminobenzanilide,4,4′-diaminophenyl benzoate, N,N′-bis(4-aminobenzyl)-p-phenylenediamine,and 4,4′-methylenebis(2-chloroaniline); melamine, 2-amino-s-triazine,2-amino-4-phenyl-s-triazine, 2-amino-4-phenyl-s-triazine,2-amino-4,6-diethyl-s-triazine, 2-amino-4,6-diphenyl-s-triazine,2-amino-4,6-bis(p-methoxyphenyl)-s-triazine,2-amino-4-anilino-s-triazine, 2-amino-4-phenoxy-s-triazine,2-amino-4-chloro-s-triazine, 2-amino-4-aminomethyl-6-chloro-s-triazine,2-(p-aminophenyl)-4,6-dichloro-s-triazine, 2,4-diamino-s-triazine,2,4-diamino-6-methyl-s-triazine, 2,4-diamino-6-phenyl-s-triazine,2,4-diamino-6-benzyl-s-triazine,2,4-diamino-6-(p-aminophenyl)-s-triazine,2,4-diamino-6-(m-aminophenyl)-s-triazine,4-amino-6-phenyl-s-triazine-2-ol, and 6-amino-s-triazine-2,4-diol, andthe like, and mixtures thereof.

Suitable cyanate ester resins include compounds of structure

wherein A is an organic or inorganic radical of valence n; and n is from1-1000 ideally 2-8, most preferably 2-4. Suitable cyanate esters usefulinclude cyanatobenzene, 1,3-4-cumylcyanatobenzene, dicyanatobenzene,2-t-butylcyanatobenzene, 2,5-di-t-butyl-1,4-dicyanatobenzene,2,5-di-t-butyl-1,3-dicyanatobenzene, 4-chloro-1,3-dicyanatobenzene,1,3,5-tricyanatobenzene, 4,4′-cyanatobiphenyl 2,2′-dicyanatobiphenyl,2,4-dimethyl-1,3-dicyanatobenzene, tetramethyldicyanatobenzene,1,3-dicyanatonaphthalene, 1,4-dicyanatonaphthalene,1,5-dicyanatonaphthalene, 1,6-dicyanatonaphthalene,1,8-dicyanatonaphthalene, 2,6-dicyanatonaphthalene,2,7-dicyanatonaphthalene, 2,2-bis(3,5-dibromo-4-cyanatophenyl)propane1,3,6-tricyanatonapthalene, 2,2-bis(4-cyanatophenyl)propane,bis(4-cyanatophenyl)methane, bis(3-chloro-4-cyanatophenyl)methanebis(3,5-dimethyl-4-cyanatophenyl)methane,1,3-bis[4-cyanatophenyl-1-(1-methylethylidene)]benzene,1,1,1-tris(4-cyanatophenyl)ethane,1,4-bis[4-cyanatophenyl-1-(1-methylethylidene)]-benzene, and the like,and mixtures thereof. The cyanate ester may be a cyanate esterprepolymer, such as, for example, prepolymers of2,2-bis(4-cyanatophenyl)-propane,bis(3,5-dimethyl-4-cyanatophenyl)methane,1,3-bis[4-cyanatophenyl-1-(1-methylethylidene)]benzene,1,4-bis[4-cyanatophenyl-1-(1-methylethylidene)]benzene,bis(4-cyanatophenyl)ether, bis(p-cyanophenoxyphenoxy)benzene,di(4-cyanatophenyl)ketone, bis(4-cyanatophenyl)thioether,bis(4-cyanatophenyl)sulfone, tris(4-cyanatophenyl)phosphite, andtris(4-cyanatophenyl)phosphate. Also useful are other cyanates asdisclosed in U.S. Pat. No. 5,215,860, col. 10, lines 19 to 38.

Cyanate ester prepolymers that can be used in the present inventioncontain free cyanate ester groups and may be produced by partial curingof the cyanate ester resin in the presence or absence of a catalyst. Atypical example of such a cyanate ester prepolymer is the partialreaction product of bis(3,5-dimethyl-4-cyanatophenyl)methane, sold underthe tradename AroCy® B-30, B-50 M-20, PT-60, PT-60S, and CT-90 by Lonza.Ltd., Switzerland. Mixtures of two or more different cyanate esterprepolymers may be used, as can mixtures of one or more cyanate esterprepolymers with one or more cyanate ester-containing compounds that arenot prepolymers. Useful cyanate esters include materials commerciallyproduced by Lonza Ltd., Switzerland and include, for example, B-10,B-30, M-10, M-30, PT-15, PT-30, PT-30S, PT-60, PT-60S, CT-90, BA-230S,L-10, F-10, RTX-399, RTX-366, and Quatrex-7187 resins

Metal salt catalysts, such as metal carboxylates can be used toaccelerate the cure rate of cyanate esters. Catalysts include manganesenaphthenate, zinc naphthenate, cobalt naphthenate, nickel naphthenate,cerium naphthenate, manganese octanoate, zinc octanoate, cobaltoctanoate, nickel octanoate and cerium octanoate, and the like.

Suitable bismaleimides include those of structure

wherein in M is a radical containing 2-40 carbon atoms of valence n andeach Z is independently a hydrogen, halogen or an aromatic or aliphaticradical and n equals 0-10. M can be aliphatic, cycloaliphatic, aromaticor heterocyclic. A preferred class of bisimides is difunctionalbismaleimides derived from aliphatic or aromatic diamines.

Specific examples of unsaturated imides include 1,2-bismaleimidoethane,1,6-bismaleimidohexane, 1,3-bismaleimidobenzene,1,4-bismaleimidobenzene, 2,4-bismaleimidotoluene,4,4′-bismaleimidodiphenylmethane, 4,4′-bismaleimidodiphenylether,3,3′-bismaleimidodiphenylsulfone, 4,4′-bismaleimidodiphenylsulfone,4,4′-bismaleimidodicyclohexylmethane,3,5-bis(4-maleimidophenyl)pyridine, 2,6-bismaleimidopyridine,1,3-bis(maleimidomethyl)cyclohexane, 1,3-bis(maleimidomethyl)benzene,1,1-bis(4-maleimidophenyl)cyclohexane,1,3-bis(dichloromaleimido)benzene, 4,4′-biscitraconimidodiphenylmethane,2,2-bis(4-maleimidophenyl)propane,1-phenyl-1,1-bis(4-maleimidophenyl)ethane,αα-bis(4-maleimidophenyl)toluene, 3,5-bismaleimido-1,2,4-triazoleN,N′-ethylenebismaleimide, N,N′-hexamethylenebismaleimide,N,N′-m-phenylenebismaleimide, N,N′-p-phenylenebismaleimide,N,N′-4,4′-diphenylmethanebismaleimide,N,N′-4,4′-diphenyletherbismaleimide,N,N′-4,4′-diphenylsufonebismaleimide,N,N′-4,4′-dicyclohexylmethanebismaleimide,N,N′-alpha,alpha′-4,4′-dimethylenecyclohexanebismaleimide,N,N′-m-xylenebismaleimide, N,N′-4,4′-diphenylcyclohexanebismaleimide,and N,N′-methylenebis(3-chloro-p-phenylene)bismaleimide, variousmaleimides disclosed in U.S. Pat. Nos. 3,562,223, 4,211,860 and4,211,861, and the like, and mixtures thereof. Maleimides can beprepared by methods known in the art, including, for example, thosedescribed in U.S. Pat. No. 3,018,290. In one embodiment, the maleimideresin is N,N′-4,4′-diphenylmethane bismaleimide.

The composition may comprise about 50 to about 99 parts by weight of thethermoplastic resin and/or thermoset resin per 100 parts by weight totalof the thermoplastic resin and/or thermoset resin and the flameretardant. Within this range, the amount of thermoplastic resin and/orthermoset resin may be at least about 60 parts by weight, or at leastabout 70 parts by weight. Also within this range, the amount ofthermoplastic resin and/or thermoset resin may be up to about 95 partsby weight, or up to about 90 parts by weight.

The composition may comprise about 1 to about 50 parts by weight of theflame retardant, based on 100 parts by weight total of the thermoplasticresin or thermoset resin and the flame retardant. Within this range, theflame retardant amount may be at least about 5 parts by weight, or atleast about 10 parts by weight. Also within this range, the flameretardant amount may be up to about 40 parts by weight, or up to about30 parts by weight.

One embodiment is a composition, comprising: (a) a thermoplastic resinselected from poly(arylene ether)s, poly(arylene sulfide)s, polyamides,polystyrenes, polyolefins, polyesters, polycarbonates,poly(styrene-co-acrylonitrile)s,poly(acrylonitrile-co-butadiene-co-styrene)s, poly(styrene-co-maleicanhydride)s, poly(acrylonitrile-co-styrene-co-acrylate)s, polyimides,polyamideimides, polyetherimides, polysulfones, polyethersulfones,polyketones, polyetherketones, polysiloxanes, and combinations thereof;and (b) a flame retardant comprising (b1) a phosphorus salt having theformula

wherein M^(d+) is Al³⁺; occurrence of R¹ and R² is independently C₁-C₆hydrocarbyl; and each occurrence of m and n is 0; and (b2) atrihydrocarbylphosphine oxide having the structure

wherein R³-R⁵ are each independently C₃-C₁₂ hydrocarbyl.

One embodiment is a composition, comprising: (a) a thermoplastic resincomprising a poly(arylene ether); and (b) a flame retardant comprisingaluminum tris(diethylphosphinate) and a phosphine oxide selected fromtriphenylphosphine oxide, allyldiphenylphosphine oxide,diallylphenylphosphine oxide, triallylphosphine oxide, and combinationsthereof.

One embodiment is a composition, comprising: (a) a thermoset resinselected from selected from epoxy resins, unsaturated polyester resins,polyimide resins, bismaleimide resins, bismaleimide triazine resins,cyanate ester resins, vinyl resins, benzoxazine resins, benzocyclobuteneresins, acrylics, alkyds, phenol-formaldehyde resins, novolacs, resoles,melamine-formaldehyde resins, urea-formaldehyde resins,hydroxymethylfurans, isocyanates, diallyl phthalate, triallyl cyanurate,triallyl isocyanurate, unsaturated polyesterimides, and combinationsthereof; and (b) a flame retardant comprising (b1) a phosphorus salthaving the formula

wherein M^(d+) is Al³⁺; occurrence of R¹ and R² is independently C₁-C₆hydrocarbyl; and each occurrence of m and n is 0; and (b2) atrihydrocarbylphosphine oxide having the structure

wherein R³-R⁵ are each independently C₃-C₁₂ hydrocarbyl.

Another embodiment is a composition, comprising: (a) a thermoset resincomprising a bisphenol A epoxy resin; and (b) a flame retardantcomprising aluminum tris(diethylphosphinate) and a phosphine oxideselected from triphenylphosphine oxide, allyldiphenylphosphine oxide,diallylphenylphosphine oxide, triallylphosphine, and combinationsthereof.

In addition to the thermoplastic resin and/or thermoset resin, and theflame retardant, the composition may comprise one or more variousadditives known in the art for thermoplastic and thermoset compositions.Suitable additives for thermoplastic compositions include, for example,plasticizers, impact modifiers, fillers, reinforcing agents (includingdisc-shaped fillers and fibrous fillers), mold release agents, colorants(including pigments and dyes), thermal stabilizers, light stabilizers,antioxidants, adhesion promoters, drip retardants, antiblocking agents,antistatic agents, blowing agents, and combinations thereof. Suitableadditives for thermoset compositions include, for example, impactmodifiers, low profile additives, cure agents, hardeners, cureinhibitors, fillers, reinforcing agents (including disc-shaped fillersand fibrous fillers), mold release agents, flow modifiers, colorants(including pigments and dyes), thermal stabilizers, light stabilizers,antioxidants, adhesion promoters, drip retardants, antiblocking agents,antistatic agents, and the like, and combinations thereof.

Apparatus and techniques for blending thermoplastic compositions andthermoset compositions are known in the art. Apparatus suitable forpreparing thermoplastic blends includes, for example, two-roll mills,Banbury mixers, and single-screw and twin-screw extruders. Apparatussuitable for preparing thermoset blends includes, for example, flasks orbeakers with mechanical stirring that are used for dissolving the PPEoligomer in a suitable solvent or curable compound. Mild heat is used tofacilitate dissolution. A square or rectangular pan containing the resinsolution is used for coating/impregnation of glass cloth via dipping thecloth into the resin solution.

The composition is useful for fabricating articles or parts of articles.Thus, one embodiment is an article comprising any of the above-describedpolymer compositions. When the composition comprises a thermoset resin,the article may comprise the composition in an uncured, partially cured,or fully cured state. Techniques for fabricating articles from thermosetcompositions are discussed below in the context of the curablecomposition comprising a functionalized poly(arylene ether) resin.Techniques for fabricating articles from thermoplastic compositionsinclude, for example, film and sheet extrusion, injection molding,gas-assist injection molding, extrusion molding, compression molding andblow molding. The article may be in the form of a film, sheet, moldedobject or composite having at least one layer comprising thecomposition.

The invention further includes a method of preparing the polymercomposition. Thus, one embodiment is a method of preparing acomposition, comprising: blending (a) a thermoplastic resin or athermoset resin; and (b) a flame retardant comprising (b1) a phosphorussalt having the formula

wherein M^(d+) is a metal ion or an onium ion; d is 1, 2, 3, or 4according to the identity of M and its oxidation state; each occurrenceof R¹ and R² is independently C₁-C₁₈ hydrocarbyl; and each occurrence ofm and n is independently 0 or 1; and (b2) a phosphine compound selectedfrom trihydrocarbylphosphines, trihydrocarbylphosphine oxides, andcombinations thereof; to form an intimate blend.

The flame retardant is particularly useful in curable compositionscomprising a poly(arylene ether) with polymerizable functionality. Thus,a third category of embodiments relates to a curable composition,comprising: (a) a functionalized poly(arylene ether) resin; (b) acurable compound selected from triallyl cyanurate, triallylisocyanurate, epoxy resins, bismaleimide resins, bismaleimide triazineresins, and combinations thereof; and (c) a flame retardant, comprising(c1) a phosphorus salt having the formula

wherein M^(d+) is a metal ion or an onium ion; d is 1, 2, 3, or 4according to the identity of M and its oxidation state; each occurrenceof R¹ and R² is independently C₁-C₁₈ hydrocarbyl; and each occurrence ofm and n is independently 0 or 1; and (c2) a phosphine compound selectedfrom trihydrocarbylphosphines, trihydrocarbylphosphine oxides, andcombinations thereof.

The curable composition comprises a functionalized poly(arylene ether).The functionalized poly(arylene ether) may be a capped poly(aryleneether), a particular type of dicapped poly(arylene ether), aring-functionalized poly(arylene ether), or a poly(arylene ether) resincomprising at least one terminal functional group selected fromcarboxylic acid, glycidyl ether, vinyl ether, and anhydride.

In one embodiment, the functionalized poly(arylene ether) comprises acapped poly(arylene ether) having the formulaQ(J-K)_(y)wherein Q is the residuum of a monohydric, dihydric, or polyhydricphenol; y is 1 to 100, more specifically 1, 2, 3, 4, 5, or 6; J has theformula

wherein R⁶ and R⁸ are each independently selected from the groupconsisting of hydrogen, halogen, primary or secondary C₁-C₁₂ alkyl,C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, C₁-C₁₂ aminoalkyl, C₁-C₁₂ hydroxyalkyl,phenyl, C₁-C₁₂ haloalkyl, C₁-C₁₂ hydrocarbyloxy, C₂-C₁₂halohydrocarbyloxy wherein at least two carbon atoms separate thehalogen and oxygen atoms, and the like; R⁷ and R⁹ are each independentlyselected from the group consisting of halogen, primary or secondaryC₁-C₁₂ alkyl, C₂-C₁₂ alkenyl, C2-C₁₂ alkynyl, C₁-C₁₂ aminoalkyl, C₁-C₁₂hydroxyalkyl, phenyl, C₁-C₁₂ haloalkyl, C₁-C₁₂ hydrocarbyloxy, C₂-C₁₂halohydrocarbyloxy wherein at least two carbon atoms separate thehalogen and oxygen atoms, and the like; m is 1 to about 200; and K is acapping group selected from the group consisting of

wherein R¹⁰ is C₁-C₁₂ alkyl; R¹¹-R¹³ are each independently selectedfrom the group consisting of hydrogen, C₁-C₁₂ alkyl, C₂-C₁₂ alkenyl,C₆-C₁₈ aryl, C₇-C₁₈ alkyl-substituted aryl, C₇-C₁₈ aryl-substitutedalkyl, C₂-C₁₂ alkoxycarbonyl, C₇-C₁₈ aryloxycarbonyl, C₈-C₁₈alkyl-substituted aryloxycarbonyl, C₈-C₁₈ aryl-substitutedalkoxycarbonyl, nitrile, formyl, carboxylate, imidate, andthiocarboxylate; R¹⁴-R¹⁸ are each independently selected from the groupconsisting of hydrogen, halogen, C₁-C₁₂ alkyl, hydroxy, and amino; andwherein Y is a divalent group selected from the group consisting of

wherein R¹⁹ and R²⁰ are each independently selected from the groupconsisting of hydrogen and C₁-C₁₂ alkyl. As used herein, the term“haloalkyl” includes alkyl groups substituted with one or more halogenatoms, including partially and fully halogenated alkyl groups.

In one embodiment, Q is the residuum of a phenol, includingpolyfunctional phenols, and includes radicals of the structure

wherein R⁶ and R⁸ are each independently hydrogen, halogen, primary orsecondary C₁-C₁₂ alkyl, C₁-C₁₂ alkenyl, C₁-C₁₂ alkynyl, C₁-C₁₂aminoalkyl, C₁-C₁₂ hydroxyalkyl, C₆-C₁₂ aryl (including phenyl), C₁-C₁₂haloalkyl, C₁-C₁₂ aminoalkyl, C₁-C₁₂ hydrocarbonoxy, C₁-C₁₂halohydrocarbonoxy wherein at least two carbon atoms separate thehalogen and oxygen atoms, or the like; R⁷ and R⁹ are each independentlyhalogen, primary or secondary C₁-C₁₂ alkyl, C₁-C₁₂ alkenyl, C₁-C₁₂alkynyl, C₁-C₁₂ aminoalkyl, C₁-C₁₂ hydroxyalkyl, C₆-C₁₂ aryl (includingphenyl), C₁-C₁₂ haloalkyl, C₁-C₁₂ aminoalkyl, C₁-C₁₂ hydrocarbonoxy,C₁-C₁₂ halohydrocarbonoxy wherein at least two carbon atoms separate thehalogen and oxygen atoms, or the like; X may be hydrogen, C₁-C₁₈hydrocarbyl, or C₁-C₁₈ hydrocarbyl containing a substituent such ascarboxylic acid, aldehyde, alcohol, amino radicals, or the like; X alsomay be sulfur, sulfonyl, sulfuryl, oxygen, C₁-C₁₂ alkylidene, or othersuch bridging group having a valence of 2 or greater to result invarious bis- or higher polyphenols; y and n are each independently 1 toabout 100, preferably 1 to 3, and more preferably about 1 to 2; in apreferred embodiment, y=n. Q may be the residuum of a monohydric phenol.Q may also be the residuum of a diphenol, such as2,2′,6,6′-tetramethyl-4,4′-diphenol. Q may also be the residuum of abisphenol, such as 2,2-bis(4-hydroxyphenyl)propane (“bisphenol A” or“BPA”).

In one embodiment, the capped poly(arylene ether) is produced by cappinga poly(arylene ether) consisting essentially of the polymerizationproduct of at least one monohydric phenol having the structure

wherein R⁶ and R⁸ are each independently hydrogen, halogen, primary orsecondary C₁-C₁₂ alkyl, C₁-C₁₂ alkenyl, C₁-C₁₂ alkynyl, C₁-C₁₂aminoalkyl, C₁-C₁₂ hydroxyalkyl, C₆-C₁₂ aryl (including phenyl), C₁-C₁₂haloalkyl, C₁-C₁₂ aminoalkyl, C₁-C₁₂ hydrocarbonoxy, C₁-C₁₂halohydrocarbonoxy wherein at least two carbon atoms separate thehalogen and oxygen atoms, or the like; and R⁷ and R⁹ are eachindependently halogen, primary or secondary C₁-C₁₂ alkyl, C₁-C₁₂alkenyl, C₁-C₁₂ alkynyl, C₁-C₁₂ aminoalkyl, C₁-C₁₂ hydroxyalkyl, C₆-C₁₂aryl (including phenyl), C₁-C₁₂ haloalkyl, C₁-C₁₂ aminoalkyl, C₁-C₁₂hydrocarbonoxy, C₁-C₁₂ halohydrocarbonoxy wherein at least two carbonatoms separate the halogen and oxygen atoms, or the like. Suitablemonohydric phenols include those described in U.S. Pat. No. 3,306,875 toHay, and highly preferred monohydric phenols include 2,6-dimethylphenoland 2,3,6-trimethylphenol. The poly(arylene ether) may be a copolymer ofat least two monohydric phenols, such as 2,6-dimethylphenol and2,3,6-trimethylphenol.

In one embodiment, the capped poly(arylene ether) comprises at least onecapping group having the structure

wherein R¹¹-R¹³ are each independently hydrogen, C₁-C₁₈ hydrocarbyl,C₂-C₁₈ hydrocarbyloxycarbonyl, nitrile, formyl, carboxylate, imidate,thiocarboxylate, or the like; R⁹-R¹³ are each independently hydrogen,halogen, C₁-C₁₂ alkyl, hydroxy, amino, or the like. Highly preferredcapping groups include acrylate (R¹¹=R¹²=R¹³=hydrogen) and methacrylate(R¹¹=methyl, R¹²=R¹³=hydrogen). It will be understood that the prefix“(meth)acryl-” means either “acryl-” or “methacryl-”.

In one embodiment, the capped poly(arylene ether) corresponds to thestructure above wherein Q is the residuum of a dihydric phenol, and y is2. For example, the capped poly(arylene ether) may comprise a dicappedpoly(arylene ether) having the structure

wherein each occurrence of Q² is independently selected from hydrogen,halogen, primary or secondary C₁-C₁₂ alkyl, C₂-C₁₂ alkenyl, C₃-C₁₂alkenylalkyl, C₂-C₁₂ alkynyl, C₃-C₁₂ alkynylalkyl, C₁-C₁₂ aminoalkyl,C₁-C₁₂ hydroxyalkyl, phenyl, C₁-C₁₂ haloalkyl, C₁-C₁₂ hydrocarbyloxy,and C₂-C₁₂ halohydrocarbyloxy wherein at least two carbon atoms separatethe halogen and oxygen atoms; wherein each occurrence of Q¹ isindependently selected from halogen, primary or secondary C₁-C₁₂ alkyl,C₂-C₁₂ alkenyl, C₃-C₁₂ alkenylalkyl, C₂-C₁₂ alkynyl, C₃-C₁₂alkynylalkyl, C₁-C₁₂ aminoalkyl, C₁-C₁₂ hydroxyalkyl, phenyl, C₁-C₁₂haloalkyl, C₁-C₁₂ hydrocarbyloxy, and C₂-C₁₂ halohydrocarbyloxy whereinat least two carbon atoms separate the halogen and oxygen atoms; eachoccurrence of R²¹ is independently hydrogen or methyl; each occurrenceof x is independently 1 to about 100; z is 0 or 1; and Y has a structureselected from

wherein each occurrence of R²², R²³, and R²⁴ is independently selectedfrom hydrogen and C₁-C₁₂ hydrocarbyl.

There is no particular limitation on the method by which the cappedpoly(arylene ether) is prepared. The capped poly(arylene ether) may beformed by the reaction of an uncapped poly(arylene ether) with a cappingagent. Capping agents include compounds known in the literature to reactwith phenolic groups. Such compounds include both monomers and polymerscontaining, for example, anhydride, acid chloride, epoxy, carbonate,ester, isocyanate, cyanate ester, or alkyl halide radicals. Cappingagents are not limited to organic compounds as, for example, phosphorusand sulfur based capping agents also are included. Examples of cappingagents include, for example, acetic anhydride, succinic anhydride,maleic anhydride, salicylic anhydride, polyesters comprising salicylateunits, homopolyesters of salicylic acid, acrylic anhydride, methacrylicanhydride, glycidyl acrylate, glycidyl methacrylate, acetyl chloride,benzoyl chloride, diphenyl carbonates such asdi(4-nitrophenyl)carbonate, acryloyl esters, methacryloyl esters, acetylesters, phenylisocyanate, 3-isopropenyl-α,α-dimethylphenylisocyanate,cyanatobenzene, 2,2-bis(4-cyanatophenyl)propane),3-(alpha-chloromethyl)styrene, 4-(alpha-chloromethyl)styrene, allylbromide, and the like, carbonate and substituted derivatives thereof,and mixtures thereof. These and other methods of forming cappedpoly(arylene ether)s are described, for example, in U.S. Pat. No.3,375,228 to Holoch et al.; U.S. Pat. No. 4,148,843 to Goossens; U.S.Pat. Nos. 4,562,243, 4,663,402, 4,665,137, and 5,091,480 to Percec etal.; U.S. Pat. Nos. 5,071,922, 5,079,268, 5,304,600, and 5,310,820 toNelissen et al.; U.S. Pat. No. 5,338,796 to Vianello et al.; U.S. Pat.No. 6,627,704 B2 to Yeager et al.; and European Patent No. 261,574 B1 toPeters et al.

A capping catalyst may be employed in the reaction of an uncappedpoly(arylene ether) with an anhydride. Examples of such compoundsinclude those known to the art that are capable of catalyzingcondensation of phenols with the capping agents described above. Usefulmaterials are basic compounds including, for example, basic compoundhydroxide salts such as sodium hydroxide, potassium hydroxide,tetraalkylammonium hydroxides, and the like; tertiary alkylamines suchas tributyl amine, triethylamine, dimethylbenzylamine,dimethylbutylamine and the like; tertiary mixed alkyl-arylamines andsubstituted derivatives thereof such as N,N-dimethylaniline;heterocyclic amines such as imidazoles, pyridines, and substitutedderivatives thereof such as 2-methylimidazole, 2-vinylimidazole,4-(dimethylamino)pyridine, 4-(1-pyrrolino)pyridine,4-(1-piperidino)pyridine, 2-vinylpyridine, 3-vinylpyridine,4-vinylpyridine, and the like. Also useful are organometallic salts suchas, for example, tin and zinc salts known to catalyze the condensationof, for example, isocyanates or cyanate esters with phenols.

In another embodiment, the functionalized poly(arylene ether) comprisesa ring-functionalized poly(arylene ether) comprising repeatingstructural units of the formula

wherein each L¹-L⁴ is independently hydrogen, a C₁-C₁₂ alkyl group, analkenyl group, or an alkynyl group; wherein the alkenyl group isrepresented by

wherein L⁵-L⁷ are independently hydrogen or methyl, and a is 0, 1, 2, 3,or 4; wherein the alkynyl group is represented by

wherein L⁸ is hydrogen, methyl, or ethyl, and b is 0, 1, 2, 3, or 4; andwherein about 0.02 mole percent to about 25 mole percent of the totalL¹-L⁴ substituents in the ring-functionalized poly(arylene ether) arealkenyl and/or alkynyl groups. Within this range, it may be preferred tohave at least about 0.1 mole percent, more preferably at least about 0.5mole percent, alkenyl and/or alkynyl groups. Also within this range, itmay be preferred to have up to about 15 mole percent, more preferably upto about 10 mole percent, alkenyl and/or alkynyl groups. Thering-functionalized poly(arylene ether) of this embodiment may beprepared according to known methods. For example, an unfunctionalizedpoly(arylene ether) such as poly(2,6-dimethyl-1,4-phenylene ether) maybe metallized with a reagent such as n-butyl lithium and subsequentlyreacted with an alkenyl halide such as allyl bromide and/or an alkynylhalide such as propargyl bromide. This and other methods for preparationof ring-functionalized poly(arylene ether) resins are described, forexample, in U.S. Pat. No. 4,923,932 to Katayose et al.

In another embodiment, the ring-functionalized poly(arylene ether) isthe product of the melt reaction of a poly(arylene ether) and anα,β-unsaturated carbonyl compound or a β-hydroxy carbonyl compound.Examples of α,β-unsaturated carbonyl compounds include, for example,maleic anhydride, citriconic anhydride, and the like. Examples ofα-hydroxy carbonyl compounds include, for example, citric acid, and thelike. Such functionalization is typically carried out by melt mixing thepoly(arylene ether) with the desired carbonyl compound at a temperatureof about 190 to about 290° C.

In one embodiment, the functionalized poly(arylene ether) resincomprises at least one terminal functional group selected fromcarboxylic acid, glycidyl ether, vinyl ether, and anhydride. Theseparticular functionalized poly(arylene ether) resins are particularlyuseful in combination with epoxy resins. A suitable method for preparinga poly(arylene ether) resin substituted with terminal carboxylic acidgroups is described in, for example, European Patent No. 261,574 B1 toPeters et al. Glycidyl ether-functionalized poly(arylene ether) resinsand methods for their preparation are described, for example, in U.S.Pat. No. 6,794,481 to Amagai et al. and U.S. Pat. No. 6,835,785 to Ishiiet al., and U.S. Patent Application Publication No. 2004/0265595 A1 toTokiwa. Vinyl ether-functionalized poly(arylene ether) resins andmethods for there preparation are described, for example, in U.S.Statutory Invention Registration No. H521 to Fan.Anhydride-functionalized poly(arylene ether) resins and methods fortheir preparation are described, for example, in European Patent No.261,574 B1 to Peters et al., and U.S. Patent Application Publication No.2004/0258852 A1 to Ohno et al.

There is no particular limitation on the molecular weight or intrinsicviscosity of the functionalized poly(arylene ether). In one embodiment,the functionalized poly(arylene ether) resin has an intrinsic viscosityof about 0.03 to about 0.6 deciliter per gram (dL/g) measured at 25° C.in chloroform. Within this range, the intrinsic viscosity may be atleast about 0.06 dL/g, or at least about 0.1 dL/g. Also within thisrange, the intrinsic viscosity may be up to about 0.5 dL/g, or up toabout 0.4 dL/g, or up to about 0.3 dL/g. Generally, the intrinsicviscosity of a functionalized poly(arylene ether) will varyinsignificantly from the intrinsic viscosity of the correspondingunfunctionalized poly(arylene ether). Specifically, the intrinsicviscosity of a functionalized poly(arylene ether) will generally bewithin 10% of that of the unfunctionalized poly(arylene ether). It isexpressly contemplated to employ blends of at least two functionalizedpoly(arylene ether)s having different molecular weights and intrinsicviscosities. The composition may comprise a blend of at least twofunctionalized poly(arylene ethers). Such blends may be prepared fromindividually prepared and isolated functionalized poly(arylene ethers).Alternatively, such blends may be prepared by reacting a singlepoly(arylene ether) with at least two functionalizing agents. Forexample, a poly(arylene ether) may be reacted with two capping agents,or a poly(arylene ether) may be metallized and reacted with twounsaturated alkylating agents. In another alternative, a mixture of atleast two poly(arylene ether) resins having different monomercompositions and/or molecular weights may be reacted with a singlefunctionalizing agent.

One embodiment is a curable composition wherein the functionalizedpoly(arylene ether) is a capped poly(arylene ether) or aring-functionalized poly(arylene ether); and wherein the curablecompound is selected from triallyl cyanurate, triallyl isocyanurate,bismaleimide resins, bismaleimide triazine resins, and combinationsthereof.

The curable composition may comprise the functionalized poly(aryleneether) in an amount of about 5 to about 80 parts by weight of thefunctionalized poly(arylene ether), based on 100 parts by weight totalof the functionalized poly(arylene ether), the curable compound, and theflame retardant. Within this range, the functionalized poly(aryleneether) amount may be at least about 10 parts per weight, or at leastabout 20 parts by weight. Also within this range, the functionalizedpoly(arylene ether) amount may be up to about 70 parts by weight, or upto about 50 parts by weight.

The curable composition comprises a curable compound selected fromtriallyl cyanurate, triallyl isocyanurate, epoxy resins, bismaleimideresins, bismaleimide triazine resins, and the like, and combinationsthereof. These curable compounds and methods for their preparation areknown in the art, and many examples are commercially available. Thecurable composition may comprise the curable compound in an amount ofabout 20 to about 95 parts by weight of the curable compound, based on100 parts by weight total of the functionalized poly(arylene ether), thecurable compound, and the flame retardant. Within this range, thecurable compound amount may be at least about 30 parts by weight, or atleast about 40 parts by weight. Also within this range, the curablecompound amount may be up to about 90 parts by weight, or up to about 80parts by weight.

In addition to the functionalized poly(arylene ether) resin and thecurable compound, the curable composition comprises the flame retardantdescribed above. The flame retardant may be present in an amount ofabout 1 to about 40 parts by weight, based on 100 parts by weight totalof the functionalized poly(arylene ether), the curable compound, and theflame retardant. Within this range, the flame retardant amount may be atleast about 10 parts by weight, or at least about 15 parts by weight.Also within this range, the flame retardant amount may be up to about 30parts by weight.

One embodiment is a curable composition, comprising: (a) a cappedpoly(arylene ether) resin; (b) a curable compound selected from triallylcyanurate, triallyl isocyanurate, bismaleimide resins, bismaleimidetriazine resins, and combinations thereof; and (c) a flame retardant,comprising a phosphorus salt having the formula

wherein M^(d+) is Al³⁺; occurrence of R¹ and R² is independently C₁-C₆hydrocarbyl; and each occurrence of m and n is 0, and atrihydrocarbylphosphine oxide having the structure

wherein R³-R⁵ are each independently C₃-C₁₂ hydrocarbyl.

Another embodiment is a curable composition, comprising: (a) a(meth)acrylate-capped poly(2,6-dimethyl-1,4-phenylene ether) resin; (b)a triallyl cyanurate, a triallyl isocyanurate, or a combination thereof;and (c) a flame retardant comprising aluminum tris(diethylphosphinate)and a phosphine oxide selected from triphenylphosphine oxide,allyldiphenylphosphine oxide, diallylphenylphosphine oxide,triallylphosphine oxide, and combinations thereof.

The invention includes partially and fully cured compositions obtainedon curing the curable composition. Curing may be effected by methodsknown in the art, including thermal curing (with or without an addedcuring agent) and photochemical curing. The invention also includesarticles formed from the curable composition. Such articles can beformed using thermoset processing methods known in the art including,for example, resin transfer molding; sheet molding; bulk molding;pultrusion; injection molding, including reaction injection molding(RIM); atmospheric pressure molding (APM); casting, includingcentrifugal and static casting open mold casting; lamination includingwet or dry lay up and spray lay up; also included are contact molding,including cylindrical contact molding; compression molding; includingvacuum assisted resin transfer molding and chemically assisted resintransfer molding; Seeman's Composite Resin Infusion ManufacturingProcessing (SCRIMP); open molding, continuous combination of resin andglass; and filament winding, including cylindrical filament winding.

The invention further includes methods of preparing the curablecomposition. Thus, one embodiment is a method of preparing a curablecomposition, comprising: blending (a) a functionalized poly(aryleneether) resin; (b) a curable compound selected from triallyl cyanurate,triallyl isocyanurate, epoxy resins, bismaleimide resins, bismaleimidetriazine resins, and combinations thereof; and (c) a flame retardant,comprising (c1) a phosphorus salt having the formula

wherein M^(d+) is a metal ion or an onium ion; d is 1, 2, 3, or 4according to the identity of M and its oxidation state; each occurrenceof R¹ and R² is independently C₁-C₁₈ hydrocarbyl; and each occurrence ofm and n is independently 0 or 1; and (c2) a phosphine compound selectedfrom trihydrocarbylphosphines, trihydrocarbylphosphine oxides, andcombinations thereof; to form an intimate blend.

The invention is further illustrated by the following non-limitingexamples.

EXAMPLES 1-4, COMPARATIVE EXAMPLES 1-7

These examples and comparative examples illustrate the flame retardantsynergy of a phosphorus salt and a phosphine compound according to theinvention. All compositions included 47.5 parts by weight triallylisocyanurate (“TAIC”), obtained from Degussa Corporation; 27.2 parts byweight of a methacrylate-capped poly(2,6-dimethyl-1,4-phenylene ether)(“MA-PPE”) having an intrinsic viscosity of 0.12 dL/g, preparedaccording to the method of U.S. Pat. No. 6,384,176 to Braat et al.; and25.3 parts by weight of glass fiber having a diameter of about 14micrometers and an initial length of about 4 millimeters, obtained as497-14C from Owens-Corning. The samples varied in their flame retardanttypes and amounts. Comparative Example 1 contained no flame retardant.Comparative Examples 2-4 contained increasing amounts of aluminumtris(diethylphosphinate) (“Al(OPEt₂)₃”), obtained as OP930 fromClariant. Comparative Examples 5-7 contained increasing amounts ofallyldiphenylphosphine oxide (“ADPPO”), obtained as from Sigma-Aldrich.Examples 1-4 contained varying amounts of both aluminumtris(diethylphosphinate) and allyldiphenylphosphine oxide. Completeformulations are given in Table 1, with component amounts expressed inparts by weight (pbw).

Curable compositions were prepared by heating at 90-95° C. a mixture ofmethacrylate-capped poly(arylene ether), triallyl isocyanurate andt-butyl catechol until the poly(arylene ether) was dissolved. Next thealuminum tris(diethylphosphinate) and allyldiphenylphosphine oxide wereadded and mixed while maintaining the temperature at 90-95° C. Then thechopped glass fiber was added and mixed while maintaining thetemperature at 90-95° C. Finally the peroxide was added, and quicklymixed. The curable compositions were molded by transferring into a 254millimeters×254 millimeters×3.175 millimeters (10 inches×10 inches×0.125inches) mold, which was preheated to 100° C. and placed in an oven at100° C. for 15-18 hours. Then the temperature was increased in steps:one hour at 110° C., two hours at 125° C., one hour at 150° C., and tenminutes at 175° C. The oven was turned off and the mold allowed to coolto ambient temperature overnight. The cured plaque was removed from themold and cut into test articles having dimensions 127 millimeters×12.7millimeters×3.175 millimeters (5 inches×0.5 inches×0.125 inches) using atile cutting saw which had a diamond cutting blade. The flame retardancyof test articles was determined according to Underwriter's Laboratory UL94 test procedure. For a V-0 rating, no individual burn times from thefirst or second flame application may exceed 10 seconds; the total ofthe burn times for any five specimens may not exceed 50 seconds; anddrip particles that ignite a piece of cotton gauze situated below thespecimen are not allowed. For a V-1 rating, no individual burn timesfrom the first or second flame application may exceed 30 seconds; thetotal of the burn times for any five specimens may not exceed 250seconds; and drip particles that ignite a piece of cotton gauze situatedbelow the specimen are not allowed. For a V-2 rating, no individual burntimes from the first or second flame application may exceed 30 seconds;the total of the burn times for any five specimens may not exceed 250seconds; and drip particles that ignite a piece of cotton gauze situatedbelow the specimen are allowed. “Flame out time (sec)” refers to theaverage flame out time per sample (averaged over five samples) in the UL94 test, expressed in units of seconds. Flame retardancy test resultsare given in Table 1. The results show that the phosphate salt andphosphine compound are both mildly effective flame retardants, and thatthe combination of the phosphate salt and phosphine compound is anextremely effective flame retardant. For example, Comparative Example 4(11.11 pbw Al(OPEt₂)₃), Comparative Example 7 (11.11 pbw ADPPO), andExample 1 (5.56 pbw each of Al(OPEt₂)₃ and ADPPO) all have the sametotal amount of flame retardant, but the respective flame out times are44.1, 104.3, and 13.2 seconds, respectively. Examples 2-4 furtherillustrate that the flame retardant combination makes it possible toachieve flame out times on the order of 5 seconds using a total of about23 parts by weight of flame retardant per 100 parts by weight total offunctionalized poly(arylene ether) and curable compound. TABLE 1 C. Ex.1 C. Ex. 2 C. Ex. 3 C. Ex. 4 C. Ex. 5 C. Ex. 6 TAIC (pbw) 47.5 47.5 47.547.5 47.5 47.5 MA-PPE (pbw) 27.2 27.2 27.2 27.2 27.2 27.2 Al(OPEt₂)₃ 02.56 5.26 11.11 0 0 (pbw) ADPPO (pbw) 0 0 0 0 2.56 5.26 Glass fibers25.3 25.3 25.3 25.3 25.3 25.3 (pbw) Flame out time 225.4 176.7 131.744.1 185.6 153.8 (sec) C. Ex. 7 Ex. 1 Ex. 2 Ex. 3 Ex. 4 TAIC (pbw) 47.547.5 47.5 47.5 47.5 MA-PPE (pbw) 27.2 27.2 27.2 27.2 27.2 Al(OPEt₂)₃(pbw) 0 5.56 5.88 11.76 7.43 ADPPO (pbw) 11.1 5.56 11.76 5.88 9.43 Glassfibers (pbw) 25.3 25.3 25.3 25.3 25.3 Flame out time 104.3 13.2 5.044.18 4.76 (sec)

EXAMPLES 5-14, COMPARATIVE EXAMPLES 8-10

These examples illustrate that the synergistic effect demonstrated inthe previous examples is also obtained when triphenylphosphine oxide isused as the phosphine compound. Triphenylphosphine oxide (“TPPO”) wasobtained from Sigma-Aldrich. Compositions were prepared, molded, andtested as described above. Compositions and results are presented inTable 2 (which reiterates the results of Comparative Examples 1-4). Theresults again show that the phosphate salt and phosphine compound areboth mildly effective flame retardants, and that the combination of thephosphate salt and phosphine compound is an extremely effective flameretardant. For example, Comparative Example 4 (11.11 pbw Al(OPEt₂)₃),Comparative Example 10 (11.11 pbw TPPO), and Example 6 (5.56 pbw each ofAl(OPEt₂)₃ and TPPO) all have the same total amount of flame retardant,but the respective flame out times are 44.1, 91.1, and 18.6 seconds,respectively. Examples 8-14 further illustrate that the flame retardantcombination makes it possible to achieve flame out times less than 10seconds using as little as 19 parts by weight of flame retardant per 100parts by weight total of functionalized poly(arylene ether) and curablecompound. TABLE 2 C. Ex. 1 C. Ex. 2 C. Ex. 3 C. Ex. 4 C. Ex. 8 C. Ex. 9TAIC (pbw) 47.5 47.5 47.5 47.5 47.5 47.5 MA-PPE (pbw) 27.2 27.2 27.227.2 27.2 27.2 Al(OPEt₂)₃ 0 2.56 5.26 11.11 0 0 (pbw) TPPO (pbw) 0 0 0 02.56 5.26 Glass fibers 25.3 25.3 25.3 25.3 25.3 25.3 (pbw) Flame outtime 225.4 176.7 131.7 44.1 162.5 131.4 (sec) C. Ex. 10 Ex. 5 Ex. 6 Ex.7 Ex. 8 Ex. 9 TAIC (pbw) 47.5 47.5 47.5 47.5 47.5 47.5 MA-PPE (pbw) 27.227.2 27.2 27.2 27.2 27.2 Al(OPEt₂)₃ (pbw) 0 5.41 5.56 5.26 10.01 4.15TPPO (pbw) 11.11 2.70 5.56 7.43 4.63 10.01 Glass fibers (pbw) 25.3 25.325.3 25.3 25.3 25.3 Flame out time 91.1 60.1 18.6 15.6 8.9 6.9 (sec) Ex.10 Ex. 11 Ex. 12 Ex. 13 Ex. 14 TAIC (pbw) 47.5 47.5 47.5 47.5 47.5MA-PPE (pbw) 27.2 27.2 27.2 27.2 27.2 Al(OPEt₂)₃ (pbw) 7.33 5.88 7.4311.76 12.50 TPPO (pbw) 10.68 11.76 9.43 5.88 12.50 Glass fibers (pbw)25.3 25.3 25.3 25.3 25.3 Flame out time 5.62 5.34 5.10 4.76 2.22 (sec)

EXAMPLES 15-54, COMPARATIVE EXAMPLES 11-17

These examples describe the fabrication of laminates using the curablecomposition. Laminates were prepared by impregnating glass cloth (17.78centimeters (7 inches) by 19.05 centimeters (7.5 inches)) with a toluenesolution of resin and flame retardant. After mixing the resin solutionfor 30 minutes, the resin solution was heated to 65° C. for 15-30seconds. After two cycles of dipping the glass cloth, the glass clothwas dried overnight by evaporation to obtain about 50 weight percentimpregnated curable composition (i.e., a “prepreg”). Laminates wereproduced by stacking several prepregs, compression molding for fourminutes at a temperature of 150-180° C. at a pressure of 13.34kilonewtons (3000 pounds), and cooling for three minutes in a hot press.The average thickness for each laminate was determined using amicrometer. Average first flame out times and average second flame outtimes were determined according to UL 94.

Compositions are presented in Table 3. In addition to componentspreviously described, the curable compositions contained the curinginitiator 2,5-bis(t-butyl peroxy)-2,5-dimethyl-3-hexyne, and the curinginhibitor tert-butylcatechol. The flammability test results, presentedin Table 3, show that the flame retardant composition makes it possibleto consistently achieve a highly desirable V-0 rating using as little as20 parts by weight of flame retardant per 100 parts by weight total offunctionalized poly(arylene ether) and curable compound. Increasing theamount of flame retardant gives better flame out times. Furthermore,greater flame out times are expected for thicker samples. TABLE 3 C. Ex.C. Ex. C. Ex. 11 12 13 Ex. 15 Ex. 16 Ex. 17 TAIC (pbw) 100 100 100 100100 100 MA-PPE (pbw) 100 100 100 100 100 100 Al(OPEt₂)₃ 0 10 0 10 10 10(pbw) TPPO (pbw) 0 0 10 10 10 10 ADPPO (pbw) 0 0 0 0 0 0 Initiator (pbw)2.02 2.02 2.02 2.02 2.02 2.02 Inhibitor (pbw) 0.205 0.205 0.205 0.2050.205 0.205 Laminate 1.39 1.50 1.47 0.76 1.63 1.17 thickness (mm)Average first 42.9 28.4 28.9 30.7 23.8 36.1 flame out time (sec) Average1.38 44.3 1.0 0.96 3.68 1.08 second flame out time (sec) UL 94 ratingV-2 V-2 V-2 V-1 V-1 V-1 Ex. 18 Ex. 19 Ex. 20 Ex. 21 Ex. 22 Ex. 23 TAIC(pbw) 100 100 100 100 100 100 MA-PPE (pbw) 100 100 100 100 100 100Al(OPEt₂)₃ 10 10 10 10 2 18 (pbw) TPPO (pbw) 10 10 10 10 18 2 ADPPO(pbw) 0 0 0 0 0 0 Initiator (pbw) 2.02 2.02 2.02 2.02 2.02 2.02Inhibitor (pbw) 0.205 0.205 0.205 0.205 0.205 0.205 Laminate 1.43 1.471.45 1.63 1.38 1.48 thickness (mm) Average first 17.0 24.9 17.7 15.814.0 24.3 flame out time (sec) Average 3.24 3.98 2.5 3.8 1.2 6.0 secondflame out time (sec) UL 94 rating V-1 V-1 V-1 V-1 V-1 V-1 Ex. 24 Ex. 25Ex. 26 Ex. 27 Ex. 28 Ex. 29 TAIC (pbw) 100 100 100 100 100 100 MA-PPE(pbw) 100 100 100 100 100 100 Al(OPEt₂)₃ 15 20 25 20 18 23 (pbw) TPPO(pbw) 15 20 25 20 15 23 ADPPO (pbw) 0 0 0 0 0 0 Initiator (pbw) 2.022.02 2.02 2.02 2.02 2.02 Inhibitor (pbw) 0.205 0.205 0.205 0.205 0.2050.205 Laminate 1.50 1.61 1.55 2.02 1.85 1.58 thickness (mm) Averagefirst 17.8 6.86 2.40 1.76 1.48 2.88 flame out time (sec) Average 5.17.46 3.62 11.36 9.18 7.86 second flame out time (sec) UL 94 rating V-1V-0 V-0 V-1 V-1 V-1 C. Ex. Ex. 30 Ex. 31 Ex. 32 Ex. 33 Ex. 34 14 TAIC(pbw) 100 100 100 100 100 100 MA-PPE (pbw) 100 100 100 100 100 100Al(OPEt₂)₃ 12 12 25 20 15 0 (pbw) TPPO (pbw) 12 12 25 20 15 0 ADPPO(pbw) 0 0 0 0 0 0 Initiator (pbw) 2.02 2.02 2.02 2.02 2.02 2.02Inhibitor (pbw) 0.205 0.205 0.205 0.205 0.205 0.205 Laminate 1.79 1.942.61 2.70 2.51 2.45 thickness (mm) Average first 2.68 2.06 1.02 1.161.18 23.22 flame out time (sec) Average 8.18 6.76 2.32 3.46 6.82 60.54second flame out time (sec) UL 94 rating V-1 V-1 V-0 V-0 V-0 V-2 Ex. 35Ex. 36 Ex. 37 Ex. 38 Ex. 39 Ex. 40 TAIC (pbw) 100 100 100 100 100 100MA-PPE (pbw) 100 100 100 100 100 100 Al(OPEt₂)₃ 20 20 20 16.5 23 20(pbw) TPPO (pbw) 20 20 20 16.5 23 20 ADPPO (pbw) 0 0 0 0 0 0 Initiator(pbw) 2.02 2.02 2.02 2.02 2.02 2.02 Inhibitor (pbw) 0.205 0.205 0.2050.205 0.205 0.205 Laminate 2.02 1.40 1.50 2.50 2.50 2.15 thickness (mm)Average first 1.28 4.16 4.36 1.12 0.96 1.00 flame out time (sec) Average15.8 0.96 2.94 12.8 7.34 8.06 second flame out time (sec) UL 94 ratingV-1 V-0 V-0 V-1 V-0 V-0 C. Ex. Ex. 41 Ex. 42 15 Ex. 43 Ex. 44 Ex. 45TAIC (pbw) 100 100 100 100 100 100 MA-PPE (pbw) 100 100 100 100 100 100Al(OPEt₂)₃ 18 15 0 25 25 25 (pbw) TPPO (pbw) 18 0 0 25 25 25 ADPPO (pbw)0 15 20 0 0 0 Initiator (pbw) 2.02 2.02 2.02 2.02 2.02 2.02 Inhibitor(pbw) 0.205 0.205 0.205 0.205 0.205 0.205 Laminate 1.65 1.50 1.50 1.601.50 1.65 thickness (mm) Average first 2.16 1.96 4.30 0.94 0.90 0.82flame out time (sec) Average 9.62 4.42 16.56 4.42 4.90 5.50 second flameout time (sec) UL 94 rating V-0 V-0 V-0 V-0 V-0 V-0 Ex. 46 Ex. 47 Ex. 48Ex. 49 Ex. 50 Ex. 51 TAIC (pbw) 100 100 100 100 100 100 MA-PPE (pbw) 100100 100 100 100 100 Al(OPEt₂)₃ 25 25 0 0 0 20 (pbw) TPPO (pbw) 25 25 2020 20 20 ADPPO (pbw) 0 0 20 20 20 0 Initiator (pbw) 2.02 2.02 2.02 2.022.02 2.02 Inhibitor (pbw) 0.205 0.205 0.205 0.205 0.205 0.205 Laminate1.70 1.55 2.78 2.86 1.60 1.90 thickness (mm) Average first 1.06 0.721.70 1.65 1.70 0.88 flame out time (sec) Average 4.28 1.43 1.38 1.282.80 1.94 second flame out time (sec) UL 94 rating V-0 V-0 V-0 V-0 V-0V-0 C. Ex. C. Ex. Ex. 52 Ex. 53 Ex. 54 16 17 TAIC (pbw) 100 100 100 100100 MA-PPE (pbw) 100 100 100 100 100 Al(OPEt₂)₃ (pbw) 20 20 25 20 0 TPPO(pbw) 20 20 25 0 20 ADPPO (pbw) 0 0 0 0 0 Initiator (pbw) 2.02 2.02 2.022.02 2.02 Inhibitor (pbw) 0.205 0.205 0.205 0.205 0.205 Laminate 1.501.60 3.14 1.50 1.50 thickness (mm) Average first 4.00 3.14 1.65 16.5614.00 flame out time (sec) Average second 1.06 1.80 2.32 4.30 1.06 flameout time (sec) UL 94 rating V-0 V-0 V-0 V-1 V-1

Dielectric properties were measured for several of the laminates.Dielectric constants (Dk) and dissipation factors (Df) were determinedat the specified frequencies according to Baker-Jarvis J., Janezic M.,Riddle B., Holloway C., Paulter N., and Blendell J. NIST Technical Note1520, Dielectric and Conductor-Loss Characterization and Measurements onElectronic Packaging Materials (sects 3.2.1 and 3.2.2), 2001. Resultsare presented in Table 4. Average values reflect two independentdeterminations. The results show that the amount of flame retardancydoes not change the dielectrics of the laminate. TABLE 4 Ex. 15 Ex. 17Ex. 20 Ex. 19 Ex. 21 Ex. 30 TAIC (pbw) 100 100 100 100 100 100 MA-PPE(pbw) 100 100 100 100 100 100 Al(OPEt₂)₃ (pbw) 10 10 10 10 10 12 TPPO(pbw) 10 10 10 10 10 12 ADPPO (pbw) 0 0 0 0 0 0 Initiator (pbw) 2.022.02 2.02 2.02 2.02 2.02 Inhibitor (pbw) 0.205 0.205 0.205 0.205 0.2050.205 Laminate thickness 0.76 1.17 1.45 1.47 1.63 1.79 (mm) Avg. Dk at10 GHz 4.15 3.42 — — — — Avg. Dk at 2.4 GHz — — 4.54 4.01 4.62 4.61 Avg.Df at 10 GHz 5.8 × 10⁻³ 5.4 × 10⁻³ — — — — Avg. Df at 2.4 GHz — — 4.5 ×10⁻³ 4.4 × 10⁻³ 4.7 × 10⁻³ 4.7 × 10⁻³ Ex. 27 Ex. 28 Ex. 29 Ex. 30 Ex. 31Ex. 32 TAIC (pbw) 100 100 100 100 100 100 MA-PPE (pbw) 100 100 100 100100 100 Al(OPEt₂)₃ (pbw) 20 18 23 12 12 25 TPPO (pbw) 20 15 23 12 12 25ADPPO (pbw) 0 0 0 0 0 0 Initiator (pbw) 2.02 2.02 2.02 2.02 2.02 2.02Inhibitor (pbw) 0.205 0.205 0.205 0.205 0.205 0.205 Laminate thickness2.02 1.85 1.58 1.79 1.94 2.61 (mm) Avg.Dk at 10 GHz — — — — — — Avg. Dkat 2.4 GHz 3.98 4.23 3.97 4.16 3.99 4.04 Avg.Df at 10 GHz — — — — — —Avg. Df at 2.4 GHz 4.4 × 10⁻³ 4.6 × 10⁻³ 4.3 × 10⁻³ 4.8 × 10⁻³ 4.3 ×10⁻³ 5.3 × 10⁻³ C. Ex. Ex. 33 Ex. 34 14 Ex. 35 Ex. 36 Ex. 37 TAIC (pbw)100 100 100 100 100 100 MA-PPE (pbw) 100 100 100 100 100 100 Al(OPEt₂)₃(pbw) 20 15 0 20 20 20 TPPO (pbw) 20 15 0 20 20 20 ADPPO (pbw) 0 0 0 0 00 Initiator (pbw) 2.02 2.02 2.02 2.02 2.02 2.02 Inhibitor (pbw) 0.2050.205 0.205 0.205 0.205 0.205 Laminate thickness 2.70 2.51 2.45 2.021.40 1.50 (mm) Avg. Dk at 10 GHz — — — — — — Avg. Dk at 2.4 GHz 4.103.93 4.02 4.23 3.70 3.80 Avg. Df at 10 GHz — — — — — — Avg. Df at 2.4GHz 4.5 × 10⁻³ 4.3 × 10⁻³ 4.4 × 10⁻³ 4.5 × 10⁻³ 4.5 × 10⁻³ 4.2 × 10⁻³ C.Ex. Ex. 38 Ex. 39 Ex. 40 Ex. 41 Ex. 42 15 TAIC (pbw) 100 100 100 100 100100 MA-PPE (pbw) 100 100 100 100 100 100 Al(OPEt₂)₃ (pbw) 16.5 23 20 1815 0 TPPO (pbw) 16.5 23 20 18 0 0 ADPPO (pbw) 0 0 0 0 15 20 Initiator(pbw) 2.02 2.02 2.02 2.02 2.02 2.02 Inhibitor (pbw) 0.205 0.205 0.2050.205 0.205 0.205 Laminate thickness 2.50 2.50 2.15 1.65 1.50 1.50 (mm)Avg. Dk at 10 GHz — — — — — — Avg. Dk at 2.4 GHz 4.35 4.42 4.41 4.164.12 4.39 Avg. Df at 10 GHz — — — — — — Avg. Df at 2.4 GHz 4.4 × 10⁻³4.5 × 10⁻³ 4.6 × 10⁻³ 4.7 × 10⁻³ 4.8 × 10⁻³ 4.9 × 10⁻³ Ex. 43 Ex. 44 Ex.45 Ex. 46 Ex. 48 Ex. 48 TAIC (pbw) 100 100 100 100 100 100 MA-PPE (pbw)100 100 100 100 100 100 Al(OPEt₂)₃ (pbw) 25 25 25 25 25 0 TPPO (pbw) 2525 25 25 25 20 ADPPO (pbw) 0 0 0 0 0 20 Initiator (pbw) 2.02 2.02 2.022.02 2.02 2.02 Inhibitor (pbw) 0.205 0.205 0.205 0.205 0.205 0.205Laminate thickness 1.60 1.50 1.65 1.70 1.55 2.78 (mm) Avg. Dk at 10 GHz— — — — — — Avg. Dk at 2.4 GHz 4.21 4.20 3.86 4.00 4.06 4.17 Avg. Df at10 GHz — — — — — — Avg. Df at 2.4 GHz 4.8 × 10⁻³ 4.7 × 10⁻³ 4.5 × 10⁻³4.6 × 10⁻³ 4.5 × 10⁻³ 4.8 × 10⁻³ Ex. 49 Ex. 50 Ex. 51 Ex. 52 Ex. 53 Ex.54 TAIC (pbw) 100 100 100 100 100 100 MA-PPE (pbw) 100 100 100 100 100100 Al(OPEt₂)₃ (pbw) 0 0 20 20 20 25 TPPO (pbw) 20 20 20 20 20 25 ADPPO(pbw) 20 20 0 0 0 0 Initiator (pbw) 2.02 2.02 2.02 2.02 2.02 2.02Inhibitor (pbw) 0.205 0.205 0.205 0.205 0.205 0.205 Laminate thickness2.86 1.60 1.90 1.50 1.60 3.14 (mm) Avg.Dk at 10 GHz — — — — — — Avg. Dkat 2.4 GHz 4.26 4.06 4.02 4.02 4.07 4.10 Avg. Df at 10 GHz — — — — — —Avg. Df at 2.4 GHz 4.8 × 10⁻³ 4.8 × 10⁻³ 4.3 × 10⁻³ 4.3 × 10⁻³ 4.4 ×10⁻³ 4.4 × 10⁻³

While the invention has been described with reference to a preferredembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims.

All ranges disclosed herein are inclusive of the endpoints, and theendpoints are combinable with each other.

All cited patents, patent applications, and other references areincorporated herein by reference in their entirety.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. Further, it should further be noted that the terms “first,”“second,” and the like herein do not denote any order, quantity, orimportance, but rather are used to distinguish one element from another.

1. A curable composition, comprising: (a) a functionalized poly(aryleneether) resin; (b) a curable compound selected from triallyl cyanurate,triallyl isocyanurate, epoxy resins, bismaleimide resins, bismaleimidetriazine resins, and combinations thereof; and (c) a flame retardant,comprising (c1) a phosphorus salt having the formula

wherein M^(d+) is a metal ion or an onium ion; d is 1, 2, 3, or 4according to the identity of M and its oxidation state; each occurrenceof R¹ and R² is independently C₁-C₁₈ hydrocarbyl; and each occurrence ofm and n is independently 0 or 1; and (c2) a phosphine compound selectedfrom trihydrocarbylphosphines, trihydrocarbylphosphine oxides, andcombinations thereof.
 2. The curable composition of claim 1, wherein thefunctionalized poly(arylene ether) is a capped poly(arylene ether) or aring-functionalized poly(arylene ether); and wherein the curablecompound is selected from triallyl cyanurate, triallyl isocyanurate,bismaleimide resins, bismaleimide triazine resins, and combinationsthereof;
 3. The curable composition of claim 2, wherein thefunctionalized poly(arylene ether) is a capped poly(arylene ether)having the structureQ(J-K)_(y) wherein Q is the residuum of a monohydric, dihydric, orpolyhydric phenol; y is 1 to 100; J has the formula

wherein R⁶ and R⁸ are each independently selected from the groupconsisting of hydrogen, halogen, primary or secondary C₁-C₁₂ alkyl,C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, C₁-C₁₂ aminoalkyl, C₁-C₁₂ hydroxyalkyl,phenyl, C₁-C₁₂ haloalkyl, C₁-C₁₂ hydrocarbyloxy, and C₂-C₁₂halohydrocarbyloxy wherein at least two carbon atoms separate thehalogen and oxygen atoms; R⁷ and R⁹ are each independently selected fromthe group consisting of halogen, primary or secondary C₁-C₁₂ alkyl,C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, C₁-C₁₂ aminoalkyl, C₁-C₁₂ hydroxyalkyl,phenyl, C₁-C₁₂ haloalkyl, C₁-C₁₂ hydrocarbyloxy, and C₂-C₁₂halohydrocarbyloxy wherein at least two carbon atoms separate thehalogen and oxygen atoms; m is 1 to about 200; and K is a capping groupselected from the group consisting of

wherein R¹⁰ is C₁-C₁₂ alkyl; R¹¹-R¹³ are each independently selectedfrom the group consisting of hydrogen, C₁-C₁₂ alkyl, C₂-C₁₂ alkenyl,C₆-C₁₈ aryl, C₇-C₁₈ alkyl-substituted aryl, C₇-C₁₈ aryl-substitutedalkyl, C₂-C₁₂ alkoxycarbonyl, C₇-C₁₈ aryloxycarbonyl, C₈-C₁₈alkyl-substituted aryloxycarbonyl, C₈-C₁₈ aryl-substitutedalkoxycarbonyl, nitrile, formyl, carboxylate, imidate, andthiocarboxylate; R¹⁴-R¹⁸ are each independently selected from the groupconsisting of hydrogen, halogen, C₁-C₁₂ alkyl, hydroxy, and amino; andwherein Y is a divalent group selected from the group consisting of

wherein R¹⁹ and R²⁰ are each independently selected from the groupconsisting of hydrogen and C₁-C₁₂ alkyl.
 4. The curable composition ofclaim 3, wherein Q is the residuum of a monohydric phenol, and y is 1.5. The curable composition of claim 3, wherein Q is the residuum of adihydric phenol, and y is
 2. 6. The curable composition of claim 2,wherein the functionalized poly(arylene ether) is a ring-functionalizedpoly(arylene ether) comprising repeating structural units having theformula

wherein each L¹-L⁴ is independently hydrogen, an alkenyl group, or analkynyl group; wherein the alkenyl group is represented by

wherein L⁵-L⁷ are independently hydrogen or methyl, and a is 0, 1, 2, 3,or 4; wherein the alkynyl group is represented by

wherein L⁸ is hydrogen, methyl, or ethyl, and b is 0, 1, 2, 3, or 4; andwherein about 0.02 mole percent to about 25 mole percent of the totalL¹-L⁴ substituents in the ring-functionalized poly(arylene ether) arealkenyl and/or alkynyl groups.
 7. The curable composition of claim 1,wherein the functionalized poly(arylene ether) resin comprises at leastone terminal functional group selected from carboxylic acid, glycidylether, vinyl ether, and anhydride; and wherein the curable compoundcomprises an epoxy resin.
 8. The curable composition of claim 1, whereinthe functionalized poly(arylene ether) has an intrinsic viscosity ofabout 0.03 to about 0.6 deciliter per gram at 25° C. in chloroform. 9.The curable composition of claim 1, comprising about 5 to about 80 partsby weight of the functionalized poly(arylene ether), based on 100 partsby weight total of the functionalized poly(arylene ether), the curablecompound, and the flame retardant.
 10. The curable composition of claim1, comprising about 20 to about 95 parts by weight of the curablecompound, based on 100 parts by weight total of the functionalizedpoly(arylene ether), the curable compound, and the flame retardant. 11.The composition of claim 1, wherein M^(d+) is an onium ion.
 12. Thecomposition of claim 1, wherein M^(d+) is a metal ion selected from ionsof magnesium, calcium, aluminum, antimony, tin, germanium, titanium,zinc, iron, zirconium, cerium, bismuth, strontium, manganese, lithium,sodium, potassium, and combinations thereof.
 13. The composition ofclaim 1, wherein M^(d+) is Al³⁺.
 14. The composition of claim 1, whereineach occurrence of R¹ and R² is independently C₁-C₆ alkyl.
 15. Thecomposition of claim 1, wherein each occurrence of R¹ and R² is methylor ethyl.
 16. The composition of claim 1, wherein M is aluminum and eachoccurrence of m and n is zero.
 17. The composition of claim 1, whereinthe phosphorus salt is aluminum tris(diethylphosphinate).
 18. Thecomposition of claim 1, comprising about 5 to about 95 parts by weightof the phosphorus salt, based on 100 parts by weight total of thephosphorus salt and the phosphine compound.
 19. The composition of claim1, wherein the phosphine compound comprises the trihydrocarbylphosphine,and wherein the trihydrocarbylphosphine has the structure

wherein R³-R⁵ are each independently C₁-C₁₂ hydrocarbyl, with theproviso that the trihydrocarbylphosphine has at least six carbon atoms.20. The composition of claim 19, wherein the trihydrocarbylphosphine isselected from triphenylphosphine, allyldiphenylphosphine,diallylphenylphosphine, triallylphosphine, and combinations thereof. 21.The composition of claim 1, wherein the phosphine compound comprises thetrihydrocarbylphosphine oxide, and wherein the trihydrocarbylphosphineoxide has the structure

wherein R³-R⁵ are each independently C₁-C₁₂ hydrocarbyl, with theproviso that the trihydrocarbylphosphine oxide has at least six carbonatoms.
 22. The composition of claim 21, wherein thetrihydrocarbylphosphine oxide is selected from triphenylphosphine,allyldiphenylphosphine oxide, diallylphenylphosphine oxide,triallylphosphine oxide, and combinations thereof.
 23. The compositionof claim 1, comprising about 5 to about 95 parts by weight of thephosphine compound, based on 100 parts by weight total of the phosphorussalt and the phosphine compound.
 24. The composition of claim 1,comprising about 1 to about 40 parts by weight of the flame retardant,based on 100 parts by weight total of the functionalized poly(aryleneether) resin, the curable compound, and the flame retardant.
 25. Acurable composition, comprising: (a) a capped poly(arylene ether) resin;(b) a curable compound selected from triallyl cyanurate, triallylisocyanurate, bismaleimide resins, bismaleimide triazine resins, andcombinations thereof; and (c) a flame retardant, comprising a phosphorussalt having the formula

wherein M^(d+) is Al³⁺; each occurrence of R¹ and R² is independentlyC₁-C₁₈ hydrocarbyl; and each occurrence of m and n is independently 0 or1; and a trihydrocarbylphosphine oxide having the structure

wherein R³-R⁵ are each independently C₃-C₁₂ hydrocarbyl.
 26. A curablecomposition, comprising: (a) a (meth)acrylate-cappedpoly(2,6-dimethyl-1,4-phenylene ether) resin; (b) a triallyl cyanurate,a triallyl isocyanurate, or a combination thereof; and (c) a flameretardant comprising aluminum tris(diethylphosphinate) and a phosphineoxide selected from triphenylphosphine oxide, allyldiphenylphosphineoxide, diallylphenylphosphine oxide, triallylphosphine oxide, andcombinations thereof.
 27. A cured composition, comprising the curedproduct of the curable composition of claim
 1. 28. An article comprisingthe composition of claim
 27. 29. A method of preparing a curablecomposition, comprising: blending (a) a functionalized poly(aryleneether) resin; (b) a curable compound selected from triallyl cyanurate,triallyl isocyanurate, epoxy resins, bismaleimide resins, bismaleimidetriazine resins, and combinations thereof; and (c) a flame retardant,comprising (c1) a phosphorus salt having the formula

wherein M^(d+) is a metal ion or an onium ion; d is 1, 2, 3, or 4according to the identity of M and its oxidation state; each occurrenceof R¹ and R² is independently C₁-C₁₈ hydrocarbyl; and each occurrence ofm and n is independently 0 or 1; and (c2) a phosphine compound selectedfrom trihydrocarbylphosphines, trihydrocarbylphosphine oxides, andcombinations thereof; to form an intimate blend.